Forget it! Why when content is already being facerolled completely by roulette players? Make the level sync more severe if anything ^_^
If you allow all skills to be used while level capped you may as well remove the level cap entirely! The point of level cap is to allow high level players to join low level players in content while protecting the enjoyment of the dungeon. It was designed carefully with particular skills / limitations in mind, and carefully balanced to be an enjoyable challenge for the average player. But in reality 90% of players will never get to experience the dungeons at the appropriate level of difficulty - instead they will be carried / dragged through in a hurry by lvl50 players.
If you're a player who enjoys being power leveled through the whole damn game then I can see the appeal, but I'm not into that and personally would love the level sync to be much much stronger. I'd also like to see end game content level synced by ilvl of gear, and that way we can avoid content being destroyed by becoming exceedingly easy to do to the point the group can pull 7 or 8 packs of mobs at once (brayflox HM) and finding a party to run the content in a normal / enjoyable manner becomes increasingly difficult. How is allowing this kind of overlevelled speed run to be possible on a massive scale good for the game in any way??
I think a good system for this would be to always lower the stats of high level gear to that of the normal quality gear you would buy from a vendor at the dungeons level range (maybe slightly higher). The synced gear should certainly never exceed the stats of the best gear obtainable withing the dungeons level range (so running coil turn 1 you can't have better stats than a player who never entered coil turn 2 or higher). The players returning already have the advantage of experience and shouldn't be given an extra handicap. The players running the content for their first time will get a truer experience, rather than a boring carry / drag through...
How much easier does the content need to be made (for repeat runners with high level gear) before someone will actually say "you know what... just pop some myth and soldiery in my mailbox everyday cause I'm really not actually playing anymore, i'm just pressing buttons".
I'm not saying the content is too easy for a party at the appropriate level, with the appropriate gear, I'm just saying that 90% of runs are too easy due to high level players (usually on roulette) being way overpowered for the content.